I assume the characters who don’t have a stage will just get an alternate version of an already existing stand.
Rash having the other piece of Downtown Demolition.
RAAM having either Hatchery or Assassins Cave
Mira with Alchemy Lab
Now for Eyedol, they could give him and Gargos two pieces of The Astral Plain. Eyedol on the left, Gargos on the right. Essentially making it a two part display set of both Shadow Lords ready to fight each other. A man can dream…
As much as I like that Killer Instinct figures exist, I seriously doubt they will ever get that far. They seem to have a hard enough time getting the rest of wave 1 (spinal and technically the large light up jago) out let alone wave 2, which was only vaguely shown a while ago and then nothing since.